Melaminium chloride hemihydrate

The crystals of a new melaminium salt, 2,4,6‐tri­amino‐1,3,5‐triazin‐1‐ium chloride hemihydrate, C₃H₇N₆⁺·Cl^?·0.5H₂O, are built up from single‐protonated melaminium residues, chloride anions and water mol­ecules. The protonated melaminium cations lie on a twofold axis, while the chloride anions and water mol­ecule lie on the m plane. The melaminium residues are interconnected by N—H?N hydrogen bonds, forming chains parallel to the (001) plane. The chains of melaminium residues form a three‐dimensional network through hydrogen‐bond interactions with chloride anions and water mol­ecules.